Generally, a connector installed at a wire to which a high-voltage current is applied has a double cutoff structure for safety. Particularly, for a hybrid vehicle to which high-voltage current is applied, this double cutoff structure is essential.
More specifically, since high-voltage current is applied to the connector, connection or disconnection of terminals of a power switch can cause arcing between the terminals, each of which acts as an electrode in this case. To prevent possible damage to a product due to the arc, an interlock switch, to which an electric current is applied at a voltage lower than that for the power switch, is further installed.
For such connector, the interlock switch to which a low-voltage current is applied is first connected or disconnected to apply or cut off power and then the power switch to which a high-voltage current is applied is connected or disconnected to prevent arcing between the terminals which is caused by application of a large amount of high-voltage current at a time.
Such connector has a first housing provided with a first power terminal and a first interlock terminal and a second terminal inserted into the first terminal. A second power terminal and a second interlock terminal to be connected respectively to the first power terminal and the first interlock terminal are installed inside the second housing such that the lengths of the first and second interlock terminals are shorter than those of the first and second power terminals.
In the connector having the above structure, when the second housing is inserted into the first housing, the first and second power terminals are first connected and then as the second housing is further inserted into the first housing the first and second interlock terminals having shorter lengths than the power terminals are connected. When the second housing is removed from the first housing, the first and second interlock terminals are first disconnected and then the first and second power terminals are disconnected.
Accordingly, the first and second interlock terminals are connected only after the first and second power terminals are connected, and thus application of supplied power is allowed only when the first and second interlock terminals are connected. Therefore, occurrence of arc due to the high-voltage current is prevented by the pre-connection of the first and second power terminals. Also, when the first and second power terminals are disconnected, arcing is prevented as the first and second interlock terminals are already disconnected and thus the power is disconnected.
However, for the conventional connector as above in which application and disconnection of power depends on whether or not the first and second interlock terminals are connected when the second housing is inserted into or removed from the first housing, it is difficult for an operator to know if the first and second interlock terminals are connected or disconnected according to insertion or removal of the second housing, and therefore it is difficult to check if high-voltage power is applied to the first and second interlock terminals.